Disaster shelter and shelter system

ABSTRACT

A disaster shelter and disaster shelter system. The disaster shelter includes a substantially hollow shelter cell having an interior and an exterior. The shelter cell is made up of three parts; a shelter body, an end cap section and an entranceway section. The shelter body is made up of a plurality of cell sections, each having a substantially identical double elliptical toroid shape, with the endmost cell sections forming an entrance end and a cap end respectively. The end cap section is joined to the cap end of the shelter body an entranceway section is joined to the entrance end of the shelter body. An entranceway is attached to the entranceway section of the shelter cell.

FIELD OF THE INVENTION

The present invention relates to the field of disaster shelters and, inparticular, to prefabricated disaster shelters and disaster sheltersystems that assembled at a remote location.

BACKGROUND OF THE INVENTION

In spite of a large amount of misinformation that has been presented tothe public, there is convincing scientific and technical informationavailable that it is possible for most people to survive a full-scaleexchange of nuclear weapons, provided that proper advance preparationsare made.

It is acknowledged that there would be little incentive for anindividual to survive such a nuclear holocaust if, as a result, all lifeon earth were doomed to extinction or marginal existence. However, theNational Academy of Sciences (NAS) has produced extensive reports on theatmospheric effects from various war scenarios, which contradict anysuch idea. In reality, therefore, the question today is not whetherpersons can survive a nuclear holocaust, but whether people have thewill and determination to prepare for survival.

Some efforts have been made to prepare shelters capable of providingsome degree of protection in the event of a nuclear blast or multipledetonations. Most such shelters were designed to afford a measure ofprotection from fallout. However, these fallout shelters provide noblast protection, nor do they protect against any number of certainother surface effects, such as a burst of nuclear radiation, thefireball which can reach millions of degrees Fahrenheit, thermalradiation transmitted from the fireball, fire storms produced by thethermal radiation, pressure waves (both under and over pressure), andblast wind.

A number of underground disaster shelters have been developed toovercome the problems attendant to traditional fallout shelters. Thetypical backyard, or personal, shelter has the capability of providingshelter for a small number of people, such as a family unit andincorporates features to protect its occupants against some of theeffects of nuclear weapons. These shelters have traditionally been builton-site, in a manner similar to “stick” construction of a home.Unfortunately, this method provides a number of drawbacks.

First, with shelters built on site, cost overruns are the rule, not theexception. Many well-intended handymen and contractors have constructedshelters that ended up running well over budget and still did notproduce an operable shelter. When a shelter is built on site, you reallydon't know what you will end up with.

Second, shelters built on site require extensive, time consuming, andexpensive research to develop a “shelter system” capable of providingdependable life support-fresh filtered air, blast protection, cleanwater, light, corrosion resistance, toilet facilities, air filtrationfor radioactive fallout, chemical and biological agents, etc. Even goodarchitects or mechanical and civil engineers, do not have the expertiseto develop a good dependable shelter system especially when it mustfunction without local electricity.

Third, concrete shelters built on site, and shelters requiring concretefoundations, are not able to be excavated and re-installed at anotherlocation and they are very hard to make waterproof, especially under thefloor.

Fourth, steel shelters have a number of specific problems attendant tothem. In particular, they may require registration because its intendeduse is for storage of petroleum and/or chemical products; a horizontalcylinder is a poor structural shape because it behaves as flexibleconduit; it must also be cathodically protected or fiberglass coated;and steel underground structures suffer from condensation on the insidewalls.

Fifth, shelters built on site require a building permit and confirmationby a local professional engineer because it involves actualconstruction, including a septic design.

Finally, shelters built on site often require many days or weeks tocomplete construction. During this time, children are exposed to thedanger of falling in the hole and curiosity seekers are afforded ampletime to see what is being constructed.

In order to overcome the problems of site-built shelters, the inventorhas developed a number of different pre-fabricated shelters and sheltersystems. One of the first such systems is disclosed in U.S. Pat. No.4,660,334, issued on Apr. 28, 1987, which is incorporated herein byreference. In this patent, the inventor of the current inventiondescribes a shelter capable of producing survival for its occupantsduring and after one or more nuclear blasts. Such a shelter is capableof withstanding large doses of neutron and gamma radiation, groundshock, and substantial over pressures, as well as a variety of otherconditions, both short and long term, enumerated in my patent.

In U.S. Pat. No. 5,115,613 issued on May 26, 1992, also incorporatedherein by reference, the inventor of the current invention describes animproved shelter having an enhanced ability to resist the blast effectresulting from the detonation of a nuclear device. The shape of thisshelter was rendered more compact and less expensive to manufacture andinstall than that of the shelter described in U.S. Pat. No. 4,660,334and the construction of the connecting shaft below the command stationwas improved such that the system better absorbed the downward forces onthe command station.

In U.S. Pat. No. 6,438,907, issued Aug. 27, 2002, also incorporatedherein by reference, the inventor of the current invention describes afurther improved shelter that includes an entranceway that includes anemergency escape manway and an entranceway that is joined to the sheltercell via a seismic joint that allows the entranceway to move relative tothe shelter cell in any manner except translation.

Each of these patented shelters is effective at resisting a blast effectfrom the detonation of a nuclear or other explosive device, and allowingits occupants to survive such a blast. In addition, each may be sealedto prevent intruders from flushing out the occupants with gasoline,water, fire, etc., and each protects against the use of a vehicle toforce open the hatch. Further, as the inventor has continually sought toimprove these products, each shelter has improved upon the prior one.

In the time since the development of the shelter and entrancewaydisclosed by U.S. Pat. No. 6,438,907, the inventor has identified anumber of areas in which the shelter and entranceway disclosed by U.S.Pat. No. 6,438,907, is lacking. First, the substantially hollowparabaloid shape of the shelter cell identified in this patent requiresthat a relatively large number of molds be used during manufacture. Thisvastly complicates the manufacturing process and effectively restrictsthe size of the shelter to the size that may be manufactured using theexisting molds. Second, the hollow parabaloid shape, can only be made inone piece to a maximum size limited by the maximum allowed shippingdimensions. Third, although the seismic joint disclosed in U.S. Pat. No.6,438,907, allows for the entranceway to move relative to the sheltercell in any manner except translation, there are circumstances wheremovement in translation is required in order to protect this joint. Forexample, the seismic joint would need to move in translation whensubjected to certain blast waves in certain soils, and especially inareas where the ground is under deep frost and the shelter is below thefrost line. Fourth, the entranceway hatch disclosed in U.S. Pat. No.6,438,907 is a hinged hatch that opens in an upward direction. Althougha jack is provided to allow the hatch to be opened even if debris hasfallen over it, extremely heavy objects may not be able to be lifted bysuch a jack and, in some cases, damage to the hinge may preventoperation thereof. Therefore, a hatch that does not open in such amanner would be desirable. Fifth, the use of an entranceway that runsstraight downward make it difficult to carry supplies into the shelterespecially with a backpack on because it requires two hand to be on theladder. Therefore, an entranceway design that allows both hands to befree when entering the shelter to carry supplies would be desirable.Finally, because the entranceway and shelter displace water, theentranceway and shelter are typically secured using a gravity dome and acable attached from the dome to the entranceway and/or shelter cell.However, over time, the tension on typical cables can vary, resulting inexcessive slack and/or excessive stress on shelter. Accordingly, adevice that would allow this tension to be adjusted would likewise bedesirable.

Therefore, there is a need for a disaster shelter for protectingshelterists during disasters such as tornadoes, storms, forest fires,power failures, nuclear power plant accidents, nuclear terrorism, and afull scale protracted nuclear, chemical, and biological war, thatincludes an entranceway that is impervious to intruders, that may bebuilt remotely from the site where it is to be installed, that reducesthe complexity of the manufacturing process, that allows a largershelter to be manufactured and still be able to be shipped on thehighway, that allows shelters of a variety of sizes by adjusting thelength, that allows each cell to move independently allowing it to bemade to have a length that is greater than 5 times the diameter withoutplacing in a high risk of catastrophic failure, that allows for asignificant amount of flexure making it substantially impervious tofailure during larger seismic events, that includes a seismic joint thatallows the entranceway to move relative to the shelter cell in anymanner including translation, that includes an entranceway hatch thatdoes not open upward, that includes an entranceway that reduces theamount of such radiation entering the shelter, and that includes adevice that would allow tension on the cables securing the shelter to agravity dome to be adjusted.

SUMMARY OF THE INVENTION

The present invention is a disaster shelter and disaster shelter systemthat overcomes the drawbacks of the prior art. In one embodiment of theinvention, the disaster shelter includes a substantially hollow sheltercell in the shape of a double elliptical arch having an interior and anexterior. The shelter cell is made up of three parts; a shelter body, anend cap section and an entranceway section. The shelter body is made upof a plurality of cell sections, each having a substantially identicalelliptical toroid shape, with the endmost cell sections forming anentrance end and a cap end respectively. The end cap section is joinedto the cap end of the shelter body an entranceway section is joined tothe entrance end of the shelter body. Finally, an entranceway isattached to the entranceway section of the shelter cell.

In the preferred embodiment, the entranceway is an ellipticalentranceway attached in non-perpendicular relation to the shelter bodysuch that it extends at an angle upward to the level of the ground. Thepreferred entranceway has a sliding hatch cover and an elliptical hatchdome ring having a slide pocket disposed therein. In such embodiments,the sliding hatch cover and the slide pocket of the hatch dome ring areeach dimensioned to allow the sliding hatch cover to slide within, andbe retained by, the slide pocket. A reduced friction material ispreferably disposed upon one of the sliding hatch cover and the slidepocket. The reduced friction material is preferably PTFE, which has asubstantially low coefficient of friction to allow the hatch cover toslide easily within the slide pocket. In order to allow the hatch coverto be moved when blocked by fallen debris, the preferred entrancewayalso includes an expanding rod removably attached to the hatch dome andthe sliding hatch cover. The expanding rod is preferably a ratchetexpanding rod having a ratchet mechanism and a handle, and isdimensioned to force the sliding hatch cover to slide within the slidepocket when the expanding rod is expanded.

The preferred disaster shelter also includes a seismic joint connectingthe entranceway to the entrance section of the shelter cell. Thepreferred seismic joint is a triple axis seismic joint that isdimensioned to allow the entranceway to move in any direction relativeto the shelter cell.

The preferred disaster shelter includes a shelter floor, disposed withinthe shelter cell, which is not attached to the shelter cell. This ispreferably accomplished by affixing a plurality of floor joint bracketsattached to the interior of the shelter cell and laying a plurality offloor planks upon the floor joint brackets, which are disposed anddimensioned to support the plurality of floor planks.

The shelter cell of the preferred disaster shelter includes a bathroomhaving a mixing exhaust manifold in communication therewith. The mixingexhaust manifold is adapted to take in gasses from both the bathroom anda remainder of the shelter cell and exhaust the gasses from the sheltercell.

The preferred disaster shelter also includes an air filtration systemdisposed within the entranceway. The preferred air filtration systemincludes an air inlet pipe, a pre-filter, a gas agent test port, a HEPAfilter, an ultraviolet light and a blower, wherein each of thepre-filter, gas agent test port, HEPA filter, and ultraviolet light arein fluid communication with the air inlet and the blower.

In another embodiment of the invention, the disaster shelter includes asubstantially hollow shelter cell having an interior and an exterior andan entranceway, and a triple axis seismic joint that connects thesubstantially hollow shelter cell to the entranceway. In suchembodiments, the triple axis seismic joint is dimensioned to allow theentranceway to move in any direction relative to the shelter cell

The disaster shelter system of the present invention includes asubstantially hollow shelter cell in the shape of a double ellipticalarch having an interior and an exterior, an entranceway attached to theshelter cell, and an entranceway anchor attached to the entranceway viaa cable. A cable tension adjuster is attached to the cable and isdimensioned to absorb shock imposed upon the entranceway. The preferredcable tension adjuster includes a substantially convex dome comprising atop half, a bottom half and a substantially flexible center donut plate.The center donut plate includes a first cable attachment, the bottomhalf includes a second cable attachment, and the top half includes anopening therethrough that is dimensioned to allow the cable to passtherethrough and attach to the first cable attachment.

In the preferred embodiment of the disaster shelter system, the sheltercell includes a toilet and the shelter system includes a leaching sseptic tank disposed a distance away from the shelter cell and in fluidcommunication with the toilet.

Therefore, it is an aspect of the invention to provide a disastershelter that is capable of resisting a blast effect from the detonationof a nuclear or other explosive device, and allowing its occupants tosurvive such a blast.

It is a further aspect of the invention to provide a disaster shelterincluding an entranceway that is impervious to intruders.

It is a further aspect of the invention to provide a disaster shelterthat prevents intruders from flushing out the occupants with gasoline,water, fire, etc..

It is a further aspect of the invention to provide a disaster shelterthat protects against the use of a vehicle to force open the hatch.

It is a further aspect of the invention to provide a disaster shelterthat has a low profile and may be easily concealed.

It is a further aspect of the invention to provide a disaster shelterthat is fully fire resistant.

It is a further aspect of the invention to provide a disaster shelterthat does not include exposed bolts that may be removed to provideingress to intruders.

It is a further aspect of the invention to provide a disaster shelterthat allows the air filtration and septic systems to be accessed fromwithin the shelter.

It is a further aspect of the invention to provide a disaster shelterthat may be assembled remotely from the site where it is to beinstalled.

It is a further aspect of the invention to provide a disaster shelterthat reduces the complexity of the manufacturing process.

It is a further aspect of the invention to provide a disaster shelterthat does not require a large number of molds to manufacture.

It is a further aspect of the invention to provide a disaster shelterthat allows shelters of a variety of sizes to be manufactured using thesame molds.

It is a further aspect of the invention to provide a disaster shelterthat allows for a significant amount of flexure making it substantiallyimpervious failure during larger seismic events.

It is a further aspect of the invention to provide a disaster shelterthat includes a seismic joint that allows the entranceway to moverelative to the shelter cell in any manner including translation.

It is a further aspect of the invention to provide a disaster shelterthat includes an entranceway hatch that does not open upward.

It is a further aspect of the invention to provide a disaster shelterthat includes an entranceway that allows both hands to be free whenentering the shelter.

It is a still further aspect of the invention to provide a disastershelter and that includes a device that would allow tension on thecables securing the shelter to a gravity dome to be adjusted.

These aspects of the invention are not meant to be exclusive and otherfeatures, aspects, and advantages of the present invention will bereadily apparent to those of ordinary skill in the art when read inconjunction with the following description, appended claims andaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cut away side view of one embodiment of the disaster shelterof the present invention.

FIG. 2 is a cut away top view of the disaster shelter of the disastershelter system of FIG. 1.

FIG: 2 is a cross sectional view taken across line A-A of FIG. 1Ashowing the interior of the disaster shelter.

FIG. 3 is an exploded isometric view of one embodiment of theentranceway of the present invention.

FIG. 4 is a top view of the preferred hatch dome ring and hatch cover ofthe present invention.

FIG. 5 is a cut away side view of the hatch dome ring, hatch cover and aportion of the entranceway.

FIG. 6A is a cut away side view of the hatch dome ring and hatch coverwith the hatch cover in a closed position.

FIG. 6B is a cut away side view of the hatch dome ring and hatch coverof FIG. 6A with the hatch cover in a partially opened position.

FIG. 6C is a cut away side view of the hatch dome ring and hatch coverof FIGS. 6A and 6B with the hatch cover in a partially opened position.

FIG. 6C is a cut away side view of the hatch dome ring and hatch coverof FIGS. 6A, 6B and 6C with the hatch cover in a fully opened position.

FIG. 7 is a cut away side view of the preferred cable tension adjusterof the disaster shelter system of the present invention.

FIG. 8 is a side view of the preferred mixing exhaust manifold of thedisaster shelter system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIGS. 1A, 1B and 2, one embodiment of the disastershelter system 10 of the present invention is shown. The disastershelter system 10 includes a disaster shelter 12 that is made up ofsubstantially hollow shelter cell 14 and an entranceway 30 attached tothe shelter cell 14.

The shelter cell 14 has an interior 15 and an exterior 16, and is madeup of three parts; a shelter body 17 an end cap section 18 and anentranceway section 19. The shelter body 17 is made up of a plurality ofcell sections, 24 each having a substantially identical doubleelliptical toroid shape, with the endmost cell sections 21 forming anentrance end 23 and a cap end 24 respectively. The end cap section 18 isjoined to the cap end 23 of the shelter body 17 and the entrancewaysection 19 is joined to the entrance end 23 of the shelter body 17.

The shelter cell 17 and entranceway 30 are preferably made of structuralfiberglass manufactured to underground storage tank standards ofUnderwriters Laboratory, American Society of Testing and Materials, andshelter engineering standards set forth in Walton W. McCarthy, M.E.,PRINCIPLES of PROTECTION, U.S. Handbook of NBC Weapon Fundamentals andShelter Engineering Standards, Fifth Edition, 2002. Fiberglass ispreferred because of its extremely high resiliency and corrosionresistance plus its ability to be shaped into a structure havingcompound curves. The fiberglass design of the preferred shelter cellprovides forty pounds per square inch of external pressure resistance,with no earth arching, which is constant over 100 years and does nothave to be de-rated like steel each passing year due to corrosion.Fiberglass also forms a complete vapor barrier, which provides a dryatmosphere when placed below ground, and has proven to be sound in theunderground storage tank industries. In addition, one of the greatestcharacteristics of fiberglass is its ability to “remain intact” ifoverstressed. The interior 15 of the shelter cell 17 is preferablysmooth, curved, and white to create maximum brightness with minimallight, is easily cleaned with common detergents, and is easily repaired.Although fiberglass is preferred, it is recognized that the shelter cell17 and/or entranceway 30 may be manufactured of different materials toachieve acceptable results.

The preferred shelter cell 17 is dimensioned to include more than fourthousand cubic feet of interior space, with headroom of between ninetyinches and one hundred and four inches from floor 25 to ceiling 27. Thisis preferred as it allows for normal living and a very spacious feeling.The preferred shelter cell also includes more than four hundred cubicfeet of storage space under the floor 25 and more than one hundred andseventy cubic feet of storage under the lower bunks 26. Such storage ispreferred to allow for the large amount of food and water necessary tosustain shelterists for extended periods of time following a disaster.Notwithstanding these preferred sizes, it is recognized that sheltercells 17 may be manufactured to a variety of different dimensions andthat the invention should not be seen as being limited to the sizes setforth herein.

The preferred disaster shelter 12 includes a shelter floor 25, disposedwithin the shelter cell 17, which is not attached to the shelter cell17. This is preferably accomplished by affixing a plurality of floorjoint brackets 29 attached to the interior 15 of the shelter cell 17 andlaying a plurality of floor planks 31 upon the floor joint brackets,which are disposed and dimensioned to support the plurality of floorplanks 31. The preferred floor joint brackets 29 are manufactured offiberglass, are shaped as shown in FIG. 2, and are attached to theinterior 15 of the shelter cell 17 via fiberglass. Further the use of aplurality of independent floor planks 31 is preferred in order to allowshelterists to easily access items stored beneath the floor 25. However,it is recognized that other flooring systems may be utilized to achievesimilar results.

As shown in FIGS. 1A and 1B, it is preferred that thirty 12-voltdeep-cycle sealed batteries 35 be stored in under the floor 25 toprovide power to the shelter 12 over long periods of time. Suchbatteries 35 are preferred as the normal loss of power therefrom isapproximately 1.5% per month. However, a photovoltaic panel (not shown)can be used to maintain the batteries 35 if desired. Further, a batterycharging cable can also be connected from the batteries 35 in theshelter 12 to the battery in a car or to an external power grid tocharge the batteries 35.

The preferred shelter cell 17 includes a bathroom 123 having a mixingexhaust manifold 125 in communication therewith. The mixing exhaustmanifold 125 is adapted to take in gasses from both the bathroom 125 anda remainder of the shelter cell and exhaust the gasses from the sheltercell. As shown in FIG. 8, the preferred mixing exhaust manifold 125includes . . .

The mixing exhaust manifold 125 is mounted on the shelter ceiling 27,which has a vent pipe 202 extending to the ground surface. The purposeof the mixing exhaust manifold is to maintain negative pressure in thebathrooms to contain bathroom odors and to still remove warm spent air,which collects at the top of the shelter 27. The air from the bathroomsenter the bottom pan 204 which is under negative pressure created by a12 volt blower positioned on blower plate 206 in the blower housing 208which operates under positive pressure. The two larger intakes on thebottom pan are sized to allow 88% of the negative pressure to berelieved through a flexible duct connected to the bathroom and 12% to berelieved by taking air through a smaller hole in the bottom pan 204. Toprevent insects from entering the mixing exhaust manifold, a 125 micronstainless steel screen is used in connection to a screen housing 210located on the top of the blower housing 208.

The entranceway 30 is attached to the entranceway section 19 of theshelter cell 17. In the preferred embodiment, the entranceway 30includes an elliptical entrance manway 34 attached in non-perpendicularrelation to the shelter body 17 such that it slopes upward at an angleto the level of the ground 100. The use of a sloped elliptical shapedentrance manway 34 is preferred as it reduces the cross sectional areaof the entranceway 30, thereby reducing the amount of radiation enteringthe shelter cell 18, while still allowing a six foot tall person 120enough headroom to stand up and use the stairs 33. In fact, the use ofan elliptical shape reduces the cross sectional area of the entrancewayby 43% when compared to a corresponding round pipe, which leads to acorresponding decrease in radiation exposure. Although this design ispreferred, as shown in FIG. 3, the entranceway 30 may extend inperpendicular to the shelter body 17 and the entrance manway 34 may beof a round cross section to achieve acceptable results.

As shown in FIGS. 3-5, regardless of whether the entranceway 30 isperpendicular or angled, or whether the entrance manway 34 is ellipticalor has some other cross sectional shape, the entranceway 30 preferablyhas a sliding hatch cover 52 and an elliptical hatch dome ring 50 havinga slide pocket 53 disposed therein. In such embodiments, the slidinghatch cover 52 and the slide pocket 53 of the hatch dome ring 50 areeach dimensioned to allow the sliding hatch cover 52 to slide within,and be retained by, the slide pocket 53. A reduced friction material ispreferably disposed upon one of the sliding hatch cover 52 and the slidepocket 53 at the interface thereof. This material is preferably PTFE,which has a substantially low coefficient of friction to allow the hatchcover 52 to slide easily within the slide pocket 53. However, othermaterials may be substituted to achieve similar results.

The hatch dome ring 50 is preferably elliptical in shape and includes anair intake vent 57 and an air exhaust vent 61 disposed therethrough.Below the hatch dome ring 50 a pocket 51 for an air filtration system 43is preferably formed within the entrance manway 34 and in communicationwith an air intake pipe 54 and a leaching septic tank 70 is preferablyattached to the outside surface of the entrance manway 34. An air outletmanifold 74 is disposed through the entrance manway 34 an incommunication with the septic vent 76 for exhausting carbon dioxide,heat and moisture from the shelter 12. The air outlet manifold 74preferably includes a stainless steel micronic screen (not shown) thatprevents pests, such as insects, scorpions, snakes or the like, fromentering the shelter 12 through the manifold 74. The manifold alsoincludes a female threaded port (not shown) to accept a threaded plugthat will allow the outlet manifold to be closed from the outsideatmosphere such as times of floods or fires on the surface.

Referring to FIGS. 3 and 4, the preferred air filtration system 43 isdisposed within the entrance manway 34 and includes a number of filterstages. Contaminated air enters the air intake vent 57 on the hatch domering 50. It then travels around under the hatch dome ring 50 where theair velocity slows, allowing rain and heavy particles to fall out.Contaminated air then travels into the vertical air intake pipe 54 underthe hatch dome and past a ball valve 56, which allows the filtrationsystem 34 to be sealed when not in use. The contaminated air thentravels into the stainless steel micronic washable screen/pre-filter 58,which removes more of the heavier particles. The air then travels intothe gas agent test housing, into which a gas agent test port 60 isdisposed. This test port 60 allows the incoming air to be tested using achemical agent test kit (not shown). The contaminated air then travelsinto the core of a HEPA/Carbon filter 202, which is preferably designedto remove 99.99% of particles that are 0.3 micron and larger, includingcarriers of biological warfare agents. The air then preferably travelsinto the activated carbon layer (not shown) to remove radioactive iodinegas, through a Whetlerite/TEDA carbon layer (not shown) to remove anychemical warfare agents, and through a filter fabric (not shown) toremove any carbon fines. The last stage of filtration is the ultravioletlight chamber 64, where viruses and bacteria are preferably exposed tomore than 11,000 microwatts seconds/cm2, effectively killing allairborne viruses and bacteria. The filtered air then enters the airblower 66, which preferably includes a centrifugal reverse curvemotorized impeller, and is exhausted into the shelter 12.

Because the air blower 66 pumps filtered air into the shelter 12, theshelter 12 is slightly pressurized. This positive pressure, plus theheat generated in the shelter 12 from body heat, cooking, and showering,forces the spent air to the highest point in shelter 12 near the top ofthe entranceway 30, where is it exhausted through the air outletmanifold 74 and out of the elliptical hatch dome air outlet vent 61.Some air will pass through and around the hatch dome 50 because thehatch dome 50 is not intended to be airtight. As the air passes aroundthe underside of the hatch dome 50, it equilibrates with the outside airresulting in little or no thermal signature because there is littlethermal difference between the spent air and ambient air.

Referring now to FIGS. 6A-6D, the preferred shelter entranceway 30includes an expanding rod 55 removably attached to the hatch dome 50 andthe sliding hatch cover 52. and dimensioned to force the sliding hatchcover 52 to slide within the slide pocket 53 when the expanding rod 55is expanded. In the event that heavy debris falls on the hatch cover 52,the expanding rod 55 may be used to force the sliding hatch cover 52open. The expanding rod 55 is preferably stored behind the ladder (notshown) and is removed and placed in position with quick acting pins 75.The rod 55 is turned manually using the ratchet lever 73 attached toproduce 10,000 pounds of force to open the hatch.

In use, the expanding rod 55 is connected as shown in FIG. 6A. Theratchet lever 73 is used to expand the expanding rod 55 to the positionshown in FIG. 6B. The end of the expanding rod 55 that is attached tothe hatch cover 52 is removed and the expanding rod 55 is retracted andattached to a second hole in the hatch cover 52 as shown in FIG. 6C. Theexpanding rod 55 is then expanded again, in the same manner as describedabove, to force the hatch cover 52 open. It is recognized that, althoughthis method is preferred, that other methods may be used. For example,hydraulic jacks or other art recognized means may be used to force thehatch cover 52 open. However, the use of an expanding rod 55 ispreferred due to its low cost, high reliability and ease of storage anduse.

Referring again to FIG. 3, the preferred disaster shelter 12 alsoincludes a seismic joint 40 connecting the entranceway to the entrancesection of the shelter cell. The preferred seismic joint is a tripleaxis seismic joint that is dimensioned to allow the entranceway to movein any direction relative to the shelter cell. The entranceway cylinder34 gets pushed down from overpressure causing the projected annular knobof the seismic joint 40 to push inward. The projecting knob of theseismic joint will react to uneven downward forces and will also allowfolding during a translation movement making the design qualify as atriple axis joint. The current design is manufactured of fiberglasshaving a thickness of approximately one inch and is sixty-two inches indiameter for a thirty six inch diameter pipe. It allows triple axismovement plus translation while maintaining water tightness, which isnecessary since virtually all underground shelter are below water tableat some point in time.

Referring again to FIG. 1, the disaster shelter system 10 of the presentinvention includes an entranceway anchor 180 which is a fiberglass domeattached to the entranceway 30 via a cable 184, which is secured to abracket 186 attached to the entranceway proximate to the surface 100 ofthe ground. However, as a cable 184 can impose a very concentrated shockload on the entranceway 30 during ground movement, a cable tensionadjuster 182 was developed in order to absorb shock and prevent shockloads from being applied to the entranceway.

As shown in detail in FIG. 7, the preferred cable tension adjuster 182includes a substantially convex dome comprising a top half 193, a bottomhalf 196 and a substantially flexible center donut plate 194. The centerdonut plate 194 includes a first cable attachment 192 and the top halfincludes an opening 190 therethrough that is dimensioned to allow thecable 184 to pass therethrough and attach to the first cable attachment192. The bottom half 196 includes a second cable attachment 199 to whicha second cable 188 is attached. The second cable 188 connects the cabletension adjuster 182 to the anchor 180. In operation, an upward load onthe entranceway 30 will cause the cable 184 to be placed in tension,which causes the center donut plate 194 to flex upward, effectivelyrelieving this load. The range of motion is approximately two inches fora thirty six inch diameter fiberglass dome which has a wall thickness ofapproximately three quarters of an inch. The annular knob is placed in acantilever load position, allowing it to flex upward.

As shown in FIG. 1, the shelter cell 17 of the preferred embodiment ofthe disaster shelter system 10 includes a bathroom 123 having a toilet124 and the shelter system 10 includes a leaching s septic tank 142disposed a distance away from the shelter cell 17 and in fluidcommunication with the toilet 124. The preferred septic tank 142 is ahalf parabaloid shaped fiberglass structure, similar in construction tothe disaster shelter described and claimed in the inventor's U.S. Pat.No. 6,385,919. However, rather than an entranceway, the septic tank 142includes a gas vent 124 in communication with the surface of the ground,and the exterior of the tank 142 includes a plurality of holes 144through which sewage may leach. Although a half parabaloid shaped tank142 is preferred, it is recognized that any number of art recognizedseptic tank designs may be substituted to achieve similar results.

As also shown in FIG. 1, the preferred disaster shelter system 10 alsoincludes a separate water tank 150 that communicates with the shelter.The preferred water tank 150 is a full parabaloid shaped fiberglass tankthat is designed for external pressure. However, tanks of other shapesor construction materials may be substituted to achieve similar results.

Although the present invention has been described in considerable detailwith reference to certain preferred versions thereof, other versionswould be readily apparent to those of ordinary skill in the art.Therefore, the spirit and scope of the appended claims should not belimited to the description of the preferred versions contained herein.

1. A disaster shelter comprising: a substantially hollow shelter cell having an interior and an exterior, said shelter cell comprising: a shelter body comprising a plurality of cell sections, wherein each cell section has a substantially identical double elliptical toroid shape, and wherein said shelter body comprises an entrance end and a cap end; an end cap section joined to said cap end of said shelter body; and an entranceway section joined to said entrance end of said shelter body; and an entranceway attached to said entranceway section of said shelter cell.
 2. The disaster shelter as claimed in claim 1, wherein said entranceway comprises an elliptical entranceway attached in non-perpendicular relation to said shelter body.
 3. The disaster shelter as claimed in claim 1 wherein said entranceway comprises a sliding hatch cover.
 4. The disaster shelter as claimed in claim 3 wherein said entranceway comprises an elliptical hatch dome ring having a slide pocket disposed therein, wherein said sliding hatch cover and said slide pocket of said hatch dome ring are each dimensioned to allow said sliding hatch cover to slide within, and be retained by, said slide pocket.
 5. The disaster shelter as claimed in claim 4 further comprising a reduced friction material disposed upon one of said sliding hatch cover and said slide pocket, said reduced friction material having a substantially low coefficient of friction.
 6. The disaster shelter as claimed in claim 4 further comprising an expanding rod removably attached to said hatch dome and said sliding hatch cover, wherein said expanding rod is dimensioned to force said sliding hatch cover to slide within said slide pocket when said expanding rod is expanded.
 7. The disaster shelter as claimed in claim 6 wherein said expanding rod is a ratchet expanding rod comprising a ratchet mechanism and a handle.
 8. The disaster shelter as claimed in claim 1 further comprising a seismic joint connecting said entranceway to said entrance section of said shelter cell.
 9. The disaster shelter as claimed in claim 8 wherein said seismic joint is a triple axis seismic joint that is dimensioned to allow said entranceway to move in any direction relative to said shelter cell.
 10. The disaster shelter as claimed in claim 1 further comprising a shelter floor disposed within said shelter cell, wherein said shelter floor is not attached to said shelter cell.
 11. The disaster shelter as claimed in claim 10 further comprising a plurality of floor joint brackets attached to said interior of said shelter cell, wherein said shelter floor comprises a plurality of floor planks, and wherein said floor joint brackets are disposed and dimensioned to support said plurality of floor planks.
 12. The disaster shelter as claimed in claim 1 wherein said shelter cell comprises a bathroom having a mixing exhaust manifold in communication therewith, wherein said mixing exhaust manifold is adapted to take in gasses from both said bathroom and a remainder of said shelter cell and exhaust said gasses from said shelter cell.
 13. The disaster shelter as claimed in claim 1 further comprising an air filtration system disposed within said entranceway.
 14. The disaster shelter as claimed in claim 13 wherein said air filtration system comprises an air inlet pipe, a pre-filter, a gas agent test port, a HEPA filter, an ultraviolet light and a blower, wherein each of said pre-filter, gas agent test port, HEPA filter, and ultraviolet light are in fluid communication with said air inlet and said blower.
 15. A disaster shelter comprising: a substantially hollow shelter cell having an interior and an exterior; an entranceway; and a triple axis seismic joint that connects said substantially hollow shelter cell to said entranceway, wherein said triple axis seismic joint is dimensioned to allow said entranceway to move relative to said shelter cell in all directions except rotation.
 16. A disaster shelter system comprising: a substantially hollow shelter cell having an interior and an exterior; an entranceway attached to said shelter cell; an entranceway anchor; a cable attaching said entranceway to said entranceway anchor; and a cable tension adjuster attached to said cable, wherein said cable tension adjuster is dimensioned to absorb shock imposed upon said entranceway; wherein said cable tension adjuster comprises a substantially convex dome comprising a top half, a bottom half and a substantially flexible center donut plate, wherein said center donut plate comprises a first cable attachment, wherein said bottom half comprises a second cable attachment, and wherein said top half comprises an opening therethrough dimensioned to allow said cable to pass therethrough and attach to said first cable attachment.
 17. (canceled)
 18. The disaster shelter system as claimed in claim 16 wherein said shelter cell further comprises a toilet and wherein said shelter system further comprising a leaching s septic tank disposed a distance away from said shelter cell and n fluid communication with said toilet. 